In his Foundation Series, SF writer Isaac Asimov prophesizes that democracy has a shelf life of only two to three centuries. Then it falls in on itself, replaced by some oligarchy.

I think most Medium political contributors fail to realize how close USA came to an oligarchy on January 6:

https://medium.com/politically-speaking/january-6-might-have-been-a-constitutional-crisis-cfcfdca6ae7

All democracies are unstable. The unwillingness to wear a mask and reduce social interactions during a pandemic speaks to the fragility of our systems.

Having said that, oligarchies like China and Saudi Arabia are also fragile. When enough people feel there is no hope for a better life, they will look for promisers.